[Lustre-devel] Stripe offset default

[Christopher J. Morrone <morrone2@llnl.gov>]

On 11/23/2010 01:19 PM, Andreas Dilger wrote:
> On 2010-11-23, at 12:49, Christopher J. Morrone wrote:
>> On 11/23/2010 09:20 AM, Eric Barton wrote:
>>> I believe, now that lfs setstripe uses options rather than positional
>>> parameters, that the risk of unintentional errors is much less.  But
>>> that still leaves the filesystem vulnerable to na?ve or malicious
>>> users.  So I propose that we should continue to check permissions
>>> normally when setting the default stripe _count_, but restrict the
>>> ability to set a specific default stripe _offset_ to the superuser.
>>
>> At the very least bug 18547 MUST be completed before doing this.
>> Lustre's default layout mechanism is too uneven, and leads to too much
>> of a performance problem right now to take away users' only ability to
>> lay files out evenly on their own.
>
> I guess the subtle distinction in Eric's question is for "default striping parameters specified on a directory" and not "striping parameters set on a per-file basis".  In IRC I discussed with Eric that it is like that specifying the starting OST on a directory default layout is _probably_ not what a user wants to do.

Ah, ok, I did miss that.  I am less opposed to that, since I can't think 
of a particularly compelling use case for a fixed offset default on 
directories.